Just a week after the United Kingdom's vote to exit the European Union rocked the continent, the country's science minister says he's “vigilant” about discrimination against U.K. scientists in European research programs. But his words appear insufficient to quell scientists' anxieties for the long term.

As long as the United Kingdom hasn't left the European Union, it is “business as usual” for Horizon 2020, the European Union's giant 7-year research program, Jo Johnson assured scientists in a speech at the Wellcome Trust in London today. Among other types of projects, Horizon 2020 provides funding for collaborative research projects, involving so-called “consortia” of scientists in several E.U. member states. There have been anecdotal reports that researchers in other countries have become reticent to include U.K. colleagues in new grant proposals because they worry that such partnerships won't endure when the divorce becomes final.

“I’ve asked the Horizon 2020 team in the Department for Business, Innovation and Skills to look out for signs that discrimination is starting to take place,” said Johnson, the minister of state for universities and science. He called on scientists to alert him if they were aware of such cases.

Johnson is the brother of former London mayor Boris Johnson, a fellow Conservative Party member who was tipped to succeed David Cameron as prime minister, but unexpectedly pulled out of the party's leadership race today. Boris staunchly campaigned to leave the European Union, whereas Jo was in favor of staying in.

Scientists for EU, a group that campaigned for the United Kingdom to remain in the European Union, is also collecting evidence of an early impact of the vote on U.K. science. “We have already heard anecdotal stories of the Brexit vote causing immediate disruption to career plans, investments, and roles in new consortia that are forming,” the group says on its website. “We need to move from rumours to a set of case studies to help inform what we need to monitor and fix.”

In Brussels, the official line matches Johnson's: All ongoing contracts will be honored, and U.K. scientists can still apply for Horizon 2020 grants as they have done until now. Johnson said that he had “preemptively” alerted Carlos Moedas, the European Commission's research chief, to his concerns. Moedas “has assured me of his support,” Johnson stated. A member of Moedas's cabinet confirms that the research commissioner spoke with Johnson on the phone today. The United Kingdom “remains a Member State with all the rights and obligations that derive from this,” he told ScienceInsider in an email.

At a commission event in Brussels on Tuesday, an attendee suggested that funding review panels might also be biased against grant proposals that include U.K. participants. A commission official responded that evaluators would receive “additional briefings” to avoid such bias.

But Johnson did not lay out a long-term future for U.K. science post-Brexit today, and said nothing to alleviate universities' worries that they will eventually lose European funding or talented researchers. The minister admitted that talks to define the new relationship between the United Kingdom and the bloc will be “a complex piece of work.” It will be hard in particular to reconcile promises to curtail the free movement of people—one of the basic tenets of the European Union, which universities want to maintain but Leave campaigners promised to curtail—with access to the European Union's single market and other benefits. Although it's important that the country remains open to the brightest people, “I can’t commit to any particular definition of freedom of movement for you,” Johnson said.